Alarm over genetic control of embryos

Sir, We are writing in regard to the HFEA’s recent consultation on what it calls “mitochondrial replacement”, about which we have a number of serious ethical concerns.

In the procedures being proposed, the chromosomes of unfertilised eggs or of newly conceived embryos are, in fact, replaced, and these are clearly examples, therefore, of germ-line genetic manipulation. The reconstructed egg or embryo will have an altered genetic composition that will be inheritable. It would be the first time such intentional genetic modifications of children and their descendants were expressly permitted and would open the door to further genetic alterations of human beings with unforeseeable consequences.

Chromosomal replacement would cross the Rubicon into germ-line genetic interventions. Moreover, we are concerned that these proposals for research and possible treatment which rely on egg donation will greatly increase the possibilities for the exploitation of egg donors.

Because of the implications for all of humanity, intentional germ-line interventions are prohibited in every national jurisdiction that has considered the issue. They are also banned under a number of international legal instruments, such as the Council of...